The copolymerization of 4-vinylbenzyl chloride(VBC) and vinyl acetate(VAC) was carried out in toluene at 75℃via radical polymerization using 2,2’-azo-bis-(isobutyronitrile)(AIBN) as an initiator.The random copolymers of poly(4-vinylbenzyl chloride-co-vinyl acetate)(P(VBC-co-VAC)) with number average molecular weight(M_n) from 2000 to 6900,relatively narrow molecular weight distribution(MWD,M_w/M_n ca.2.0) and with different copolymer composition of 4-vinylbenzyl chloride(VBC) from 17 mol%to 62 mol%could be obtained.The P(VBC-co-VAC) copolymers with an average number of 7 to 13 initiating sites of benzyl chloride per macromolecule could be used for the cationic polymerization of isobutylene(IB).The cationic polymerizations of IB were further conducted by using P(VBC-co-VAC) copolymers as macroinitiators in conjunction with TiCl_4 at -40℃in CH_2Cl_2.The effects of VBC/TiCl_4(molar ratio) on monomer conversion,M_n and MWD of the resultant copolymers were investigated under 3 sets of conditions.It is found that P(VBC-co-VAC)-g-PIB copolymers with relatively narrow MWD(M_w/M_n ca.2.0) and with terminal tert-chlorine functional groups in branched PIB chains could be successfully synthesized when VBC/TiCl_4(molar ratio) was set in the range from 0.10 to 1.12.The unimodal GPC curve of the P(VBC-co-VAC)-g-PIB copolymers by RI detector was almost in harmony with the GPC curve by UV detector.The TEM image of the P(VBC-co-VAC)-g-PIB copolymer stained by RuO indicated that the copolymer formed a two-phase morphology with P(VBC-co-VAC)-rich domains of 20-100 nm in size tethered by PIB branch segments. The copolymerization of 4-vinylbenzyl chloride (VBC) and vinyl acetate (VAC) was carried out in toluene via radical polymerization using 2,2’-azo- bis- (isobutyronitrile) (AIBN) as an initiator. of poly (4-vinylbenzyl chloride-co-vinyl acetate) (P (VBC-co-VAC)) with number average molecular weight (M_n) from 2000 to 6900, relatively narrow molecular weight distribution (MWD, M_w / M_n ca.2.0 ) with different copolymer composition of 4-vinylbenzyl chloride (VBC) from 17 mol% to 62 mol% could have been obtained. P (VBC-co-VAC) copolymers with an average number of 7 to 13 initiating sites of benzyl chloride per The cationic polymerizations of IB were further conducted by using P (VBC-co-VAC) copolymers as macroinitiators in conjunction with TiCl 4 at -40 ° C. in CH 2 Cl 2. The effects of VBC / TiCl_4 molar ratio on monomer conversion, M_n and MWD of the resultant copolymers were investigated under 3 sets of c (VBC-co-VAC) -g-PIB copolymers with relatively narrow MWD (M_w / M_n ca. 2.0) and with terminal tert-chlorine functional groups in branched PIB chains could be successfully synthesized when VBC / TiCl_4 molar ratio was set in the range from 0.10 to 1.12. The unimodal GPC curve of the P (VBC-co-VAC) -g-PIB copolymers by RI detector was almost in harmony with the GPC curve by UV detector. TEM image of the P (VBC-co-VAC) -g-PIB copolymer stained by RuO indicated that the copolymer formed a two-phase morphology with P (VBC-co- VAC) -rich domains of 20-100 nm in size tethered by PIB branch segments.